Machine for constricting tubes



April 15, 1952 I o. F. A. BlGlNELLl 2,592,593

MACHINE FOR CONSTRICTING TUBES Filed May 7, 1948 5 Sheets-Sheet l mvam-ozz OEEsTE FLAv/o ALFzs BIG/NELL/ Aiorneg April 1952 o. F. A. BIGINELLI 2,592,593

' MACHINE FOR CONSTRICTING TUBES Filed May 7, 1948 3 Sheets-Sheet 2 Figw lrwzwmz: URESTE FLAWO ALFRED B/G/NEZ-L/ AHorney April 15, 1952 o. F; A. BlGlNELLl 2,592,593

MACHINE FOR CONSTRICTING TUBES Filed May 7, 1948 3 Sheets-Sheet 5 a i i 5 0R5 s75 FLA VIOAL'FEED BIG/HELL! Byo OIMJZJ A a! 50m 05 Patented Apr. 15, 1952 MACHINE FOR CONSTRICTING TUBES Oreste Flavio Alfred Biginelli, Clermont-Ferrand, France; vested in the Attorney General of the United States Application May 7, 1948, Serial No. 25,694 In France September 19, 1940 Section 1, Public Law 690, August 8, 1946 Patent expires September 19, 1960 (C1. Ill-52) 3 Claims.

This invention relates to a method for constricting a tube and to a machine for carrying out said method, being a continuation of my prior application Serial No. 435,234, filed March 18,

1942-, now abandoned.

constricting methods are already known in which a tube maintained in a chuck is shifted axially so as to force its end into a rotary die centered on the axis of the tube.

In these known methods the die attacks the end of the tube on a sharp edge of the latter which causes an untimely wear of the die in the parts which first come into contact with the tube. Furthermore, the free end of the tube is urged in rotation by the die which gives rise to torsional stresses in the tube.

Methods are also known in which the tube is clamped at one end in a stationary chuck and maintained by a strap or clamp between said chuck and the die which rotates around its own axis while being forced axially against the end of the tube.

In this case the strap is used for centering the tube but it does not maintain this tube against torsional stresses. The die also wears away very rapidly in its part which first comes into contact with the tube.

The present invention has for its object to avoid these drawbacks and to make it possible to perform the constriction irrespective of its magnitude and to obtain a rapid operation, the advancing time of the die amounting only to a few seconds, the arrangement being such that this method can be applied to both ends of the tube successively.

According to the invention the method which makes it possible to attain the above mentioned objects shows the features which result from the following description and especially from the appended claims.

The appended drawings show by way of example the method of operation for the constriction by means of the necessary device which is also shown.

Figures 1, 2 and 3 show the various steps of the method, the views being fragmentary diagrammatic axial sections of parts of the machine illustrated in Figures and 10A and the tube being acted upon.

Figures 4, 5, 6, 7, 8 and 9 show various forms of constrictions and the dies making it possible to obtain the same, the successively related figures illustrating the dies and tube formations produced thereby, in section.

Figures 10 and 10A are front elevations partly broken away and in axial section of disassociated opposite end portions of the machine which is used for carrying out the methods in accordance with the invention.

The equipment essentially comprises a press frame including, on one side, a device for obtaining a double acting press movement along the longitudinal axis and, on the other side, a plate to which a movement of rotation around said axis is imparted.

I is an extension of the press slide or piston rod which can be shifted longitudinally without being able to rotate around the axis owing to the fact that it is guided on the pillars which are fast with the frame.

The extension I of the slide receives a clamping chuck which makes it possible to hold fast this end of the tube which is opposed to the end to be constricted. In the example of Figure 1 this clamping chuck is formed of the three following elements:

(1) a stop 2 for an end of the tube before or after being formed, produced at or in the end of the extension I by said chuck or a cavity formed at said end, forming a socket for the tube;

(2) a clamping member with a conical outer shape and a cylindrical inner shape fitting the outside of the tube, said clamping member being divided into sectors by planes passing through the axis;

(3) a clamping chuck 4 screwed on I and having an inner conical shape corresponding to the external shape of the sectors 3. When said chuck is screwed on I the sectors 3 are clamped on the tube previously encased in socket 2, thus rendering the tube fast to or fixed with the press slide, to cause it to move axially with the longitudinal press movement.

5 shows the plate anti-irictionally journaled in the frame to which a movement of rotation around the axis is imparted and which is stopped against the frame in both directions as by supporting and oppositely acting end thrust bearings so as to be unable to move longitudinally.

The constriction tool equipment comprises:

(1) a rotary die (5 encased and fixed in plate 5 which imparts its movement of rotation to said die through the medium of the keying '1, and

(2) a die 8 fast with the press frame held in any suitable manner as by a spanner or ring nut or otherwise as at 28 and disposed in juxtaposition to and ahead of the rotary die 6 but preferably with a slight spacing or clearance therebetween and slightly constricted or curved in longitudinal cross-section interiorly toward the rotary die 6 to cause a constriction of the tube as it passes through said fast or stationary die 8.

It will be seen from the drawings that the action of this stationary fixed die is, by reason of the outlet end being smaller than its inlet end, to effect primary reduction of the tube diameter before the revolving die 6 is reached by reason of the direct lineal movement of the tube and that the reduction in diameter of the tube by the die 8 also causes the tube to be so tightly forced into and through the fixed die 8 that the latter has, besides its function'of reducing the tube diameter also that of acting as a gripping device to steady and hold the tube against rotation, thus reducing the tortional stress imparted to the tube body while it is being acted on by the rotary die 6. The taper of the opening in the die 8 merges smoothly into the working face of the die 6.

The method of operation for the constriction is the following.

The press slide being in the position shown in Figure 1 the tube 9 is put in place on or in the clamping chuck 4 against stop 2 and clamped by turning same to contract sectors 'or jaws 3 thereon.

A movement of rotation is imparted to die '6 and the press movement is started toward the left.

The end of the tube first enters the stationary die 8 which compels said tube to center itself exactly on the axis while submitting it to a first constriction-of comparatively small magnitude. The tube. then assumes the shape H] shown'in Figure 2.

This die also opposes the rotation of the tube,

.at least partially, owing to the clamping of said tube, thus reducing the torsional stress imparted to the tube body through the action of the rotary die.

The press movement further continuing toward the left the end wall of the tube comes into contact with the rotary die 6. Since the tube cannot rotate owing to the fact that it is clamped on stop 2 of the press slide and held fast in the annular stationary die 8, a considerable friction arises between the end wall of the tube and the rotary die wihence a heating which renders the metal of said wall sufficiently malleable in order that the press movement compels it to take the shape of the rotary die.

The bore or cavity of the annular stationary die 8 is such as to easily but frictionally receive in the direction of the length of the tube the end of the tube to-be acted upon or formed to constrict same without permitting the die to attack or engage the end of the tube or the sharp edge at said end coming in contact with the die so as to cause undesirable or rapid wear on the latter, but the .die is .so curved in longitudinal cross-section toward the constricted portion as to gradually merge therewith and cause a constriction, preferably gradual and slight, of the tube end as it passes through the die, so that the first constriction is of comparatively small magnitude and the second or subsequent constriction and shaping of the tube end is more quickly, easily and smoothly effected by the wall of the cavity of the rotary die 6 and mergence of the cavity of the die 3 therewith or vice versa. However, the'tube end is sufficiently gripped by the friction between it and the stationary die 8 as to oppose or resist rotation of the tube in connection with the same being held fast .in the chuck 4 of the press slide as to reduce tortional stress while causing sufiicient friction between the tube and rotary die as to heat and render the tube end sufilciently malleable as to hasten the final constriction and shaping and greatly expedite the same without injury to the dies, thereby appreciably extending their useful lines. At the end of the operation the tube has taken the shape I I in Figure 3.

As soon as the constriction is achieved the press slide is returned back, i. e. to the right, so as to take again the position shown in Figure 1. In this movement the constricted end is drawn out of both dies 8 and 8 and the tube can be released by unclamping the clamping chuck.

As explained above, the shape of the stationary die 8 and of the rotary die 6 must be suitably chosen for the constriction shape to be obtained.

By way of example, Figure 4 shows at I! and '13 respectively the shape to be given to the stationary die and to the rotary die in order to obtain the constriction shape shown in Figure 5 and comprising a mouth.

Figure 6 shows at Hi and i5 the shape which is necessary for obtaining the constrictionshown in Figure '7 and Figure 8 shows at [6 and I] the shape which is necessary for obtaining the constriction in which the metal is forced inwardly as shown in Figure 9.

The method which makes it possible to obtain a hollow constriction according to the invention can be applied to both ends of the tube successively, thus making it possible to obtain from a tube a piece shaped like a bottle or vessel with two mouths which was not possible with the methods of constriction requiring a ,mandrel with an internal shape. The only modification to be provided in the above described equipment in order to obtain the second constriction of the tube consists in adapting the clamping chuck i of the press slide so that the latter can receive and hold fast the tube end which received the first constriction. Press slide extension I or chuck 4 is preferably hollowed out as shown, to accommodate the first constriction.

Figure 10 shows, by way of example, a form of execution of a machine for carrying out the method in accordance with the invention.

Mounted on the frame it! of the machine, on V the one side, is a double acting hydraulic press cylinder l9 of which 20 and 2B are the inlets for the fluid coming from the pump. The end of the piston rod or extension I is guided through a-slide 22 and carries the clamping chuck 3.

On the other side the frame carries the system imparting a movement of rotation to the rotary die. Said system is formed of an electric motor 24 which actuates the rotary plate 5 through the medium of a speed variator 26.

Plate 5 is mounted on ball and. thrust bearings so as to be able to rotate without moving inthe longitudinal direction under the action .of the press. It carries the rotary die 6 which is encased and keyed on the face corresponding to the press; the speed variator makes it possible to give the rotary die a speed of rotation suitably chosen according to the diameter, the thickness and the nature of the metal of the tube to be shaped.

The stationary die 8, which is fast with the frame of the machine, is arranged with a slight play against the external face of the rotarydie 6.

I claim:

1. In a machine for constricting the end of a tube, a frame, a non-rotary chuck mounted on said frame-to slide along its axis, means for moving said chuck on the frame, a rotary die centered on the axis of the chuck, means for driving said die rotatively about its axis, means for preventing any axial movement of said rotary die, and a stationary annular die centered on the axis common to the chuck and the rotary die disposed ahead of and in the immediate vicinity of said rotary die for receiving and centering the end of the tube, said stationary die being slightly constricted interiorly toward the rotary die for starting and causing a constriction of the tube end as it passes through said stationary die and opposing rotation of the tube by frictional engagement therewith upon entering and being acted upon by the rotary die, thus reducing the torsional stresses imparted to the tube body through the action of the rotary die.

2. In a machine for constricting the end of a tube, a frame, a non-rotary chuck mounted on said frame to slide along its axis, means for moving said chuck on said frame, a hollow rotary die centered on the axis of the chuck, the hollow portion of which has the exact shape of the constriction desired, means for driving said die rotatively about its axis, means for preventing any axial movement of said rotary die, and a stationary annular die centered on the axis common to the chuck and the rotary die, :being curved in longitudinal cross-section to cause a restriction of the tube end as it passes through said die disposed ahead of and in the immediate yicinity of said rotary die, said annular die having an interior profile which extends that 01' the rotary die for 0 centering the end of the tube, and holding it against all rotation, and starting its constriction, diu'ing the same operative pass which produces the complete shaping of the tube.

3. In a machine for constricting the extremity of a tube, a frame, a non-rotative chuck mounted on said frame in order to slide along its axis, means for shifting said chuck on said frame, a, rotary die centered on the axis of the chuck, means for rotating said die around its axis, means for opposing any axial displacement of said rotary die, a stationary annular die, the passage section of which is restricted towards the rotary die, said stationary annular die being centered on the common axis of the chuck and of the rotary die and arranged in front of and close to said rotary die in order to start the constriction of the extremity of the tube while insuring its centering and its maintenance against any rotation through jamming.

ORESTE FLAVID ALFRED BIGmELLI.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 444,721 Bevington Jan.. 13, 1891 1,297,819 Perrier Mar. 18, 1919 1,436,489 Ferrier Nov. 21, 1922 2,030,818 Harter Feb. 11, 1936 

